Piston skirt expander



April so, 194o. Q A AMEN 2,198,829

' PISTON SKIRT EXPANDER Filed March 6, 1939 #521/4 I HrroR/VEK Patented Apr. 30, 1940 UNITED STATES PATENT OFFICE PISTON SKIRT EXPANDER Charles A. Marien, St. Louis, Mo., assigner to Ramsey Accessories Manufacturing Corporation, St. Louis, Mo., a corporation of Missouri Application March 6, 1939, Serial No. 259,963

6 Claims.

that shown in Patent No. 1,806,416 granted toA Harold F. Phillips and reissued as No. 18,653 on lu November 15, 1932, and While it has the same general objects as those embodied in the Phillips patent, it embodies features of construction whereby it has a more universal application to pistons of dilferent design than the Phillips conl struction, and it also embodies more reliable anf choring means.

The present expander also embodies structural features which insure that it will remain securely xed in position within the skirt notwithstanding V2o the inertia and vibration to which it is subjected when the piston is traveling at extremely high speeds. The construction of my improved skirt expander is such that it automatically adapts itself while being fitted into the piston skirt to 25 variations and imperfections that occur in the general run of pistons. 'I'hese features as well as others inherent in the invention will be better apparent from a detailed description of the same in connection with the accompanying drawing, 30 in which: p

Figure 1 is a combination side elevation and middle vertical section, taken through a conventional type of piston showing my improved skirt expander mounted on the piston pin and eXertaliA ing its tension on the lower part of the piston skirt; Fig. 2 is a bottom plan of the piston showing the skirt expander secured therein; Fig. 3

is a vertical longitudinal section taken 'through the piston skirt on the line 3-3 of Fig. 1; Fig. 4

40 is an enlarged fragmentary view of the skirt expander showing in combined section and elevation the portion thereof where the expanding part of the expander and the supporting ear are joined together; Fig. 5 is a cross-sectional detail 46 taken on the line 5-5 of Fig. 4; Fig. Gis a bottom plan of that portion of the expander shown in Fig. 4 showing in dotted lines the relative movement that is possible between the supporting 4ears and the expander proper in order to com- 50 pensate for irregularities in the pistons, and thereby allow for lack ofabsolute parallelism of the faces of the piston pin bosses; Fig. 7 is a combined side elevation and vertical longitudinal section on a reduced scale of a piston skirt show- Y 55 ing a slightly different form of skirt expander which has been dislodged from its initial position through the force of inertia and of the impact of the explosion during the operation of the engine: (this view is for comparison only with Fig` 1); and Fig. 8 is a side elevation on a re duced scale of a different type of piston having a solid non-slotted skirt.

Referring to the drawing, P represents a piston of a typical construction having its skirt I slotted at 2 immediately below the bottom ring land 3. 10, 'The skirt is also provided with a longitudinal slot l extending from slot 2 to the bottom of the piston skirt. Slot l is approximately midway between the piston pin bosses 5, 5 and, as well understood, is provided for the purpose of allowl5 ing the to contract circumferentially to compensate for expansion caused by heat during the operation of the engine. Of course, in the case of cast iron or steel pistons these slots. are generally not provided. Such a piston is shown in Fig. 8, and the invention is in no wise dependent for its usefulness on a slotted piston. In order to restore to its proper shape a piston skirt that has been distorted or worn in use a piston skirt expander 6 is securely mounted With- 25 in the skirt.

My improved expander embodies an annular spring member 'l having parallel sides 8, 8 and arcuate skirt expanding parts 9, 9, separated by a gap l0, and It extending continuously from one side 8 to the other. The general shape of the spring member `Il is similar to that shown in my Patent No. 1,887,769. However, in the present case the spring member l is secured Within the skirt by a pair of oppositely disposed ears I2, I2 terminating in lobate members I3, I3, each of which is provided with an opening I4 for the reception of the piston pin I4. The ears I2 terminate at their lower ends in three gripping fingers l5, I5 and I6 disposed therebetween, the i0 latter having a bead Il extending inwardly for a purpose presently to appear. The spring member 6 and ears l2, l2 are maintained in assembled relation by forcing the sides 8, 8 within the oppositely disposed sets of ngers.

The central nger I6 on each side will of course yield so that the side 8 may pass beyond the crimp I1, after which this lfinger will snap together and member 8 be securely held within the finger. A slight clearance a. is providedbetween the base of the crimp Il and the inner surface b of the side 8 so that the ear I2 may be capable of a lateral rocking movement as indicated by the dotted lines in Fig. 6. This lateral rocking movement allows for an automatic adjustment new pistons.

It will be observed (Figures l and 4) that the intermediate part 8' which receives the ngers I5, I5 and I6 is offset from the balance of 'the side member 8 soas to form shoulders s, s which serve as abutments for the outer edges of fingers I5, I5 and thus prevent movement of the ears I2, I2 on the side members 8, 8. Were it not for this offset with .its shoulders s, s the spring member 6 would be free to slide through the fingers I5, I5 and I5 and become displaced. as shown in construction illustrated in Fig. land just 'de- Fig. '7, under the hammering action to which 'the piston is subjected during the operation of Ithe engine as alluded to above. However, due tothe scribed, any tendency' on the part of the spring member 6 to become displaced will .be resisted by the ears I2, I2 so that the entire skirt expander` assembly will remain rigidly in place un-- der the most severe operating conditions.

In Fig. 8 I.illustrate a piston P', the skirt of which'is not slotted, as it-is within the scope of the present invention.

Having described my invention, Iselaim:

1. -A skirt expander for pistons having oppositely disposed piston pin bosses for the lreception oi a piston pin, said expander comprising an vexpanding part having side members and piston engaging members adapted to engage the opposite sides of the piston skirt intermediate of the bosses, and supporting members for said expanding part, said supporting members having ngers for gripping vsaid side members and having lobate elements for the reception ofthe piston pin.

2. A skirt expander for pistons having oppositely disposed piston pin bosses for the reception or a piston pin?,A said expander comprising an abutment means on the side members adapted to engage the supporting members.

3. A skirt expander for pistons having oppositely disposed piston pin bosses for the reception of a. piston pin, said expander comprising an expanding part having side members and pis- `elements for the reception of the piston pin, and f ton engaging members adapted to engage the opposite sides of the piston skirt intermediate of the bosses, and supporting members for said expanding part, said supporting members having ngers for gripping said side members and having lobate elements for the reception of the vpiston Din, and abutment means adapted'for engagement withthe supporting members.

4. A piston skirt expander comprising an expanding part and supporting members movably connected thereto, said supporting members having clamps for engaging the expanding part, and

cooperating means on said members and expanding part holding the supporting members against movement lengthwise of the expanding part. l

5. A piston skirt expander comprising an expanding part having side members and pistonv engaging members, a supporting member movably secured to each of said side members, abutment means onv each sidel member adapted. for

Y engagement with the adjacent edges oi the supporting member,

`6. A piston skirt expander comprising an expanding part for engagement with the piston -expanding part, with clearance to permit automatic adjustment of the supporting members in the piston. l

Y CHARLES A. MARIEN. 

